Experimental infection with an Allerton-type herpesvirus of buffalo origin (BA) was studied in East African grade cattle inoculated by different routes. Intravenous inoculation of large doses caused skin lesions in only 4 of 10 cases. Epithelial necrosis and erosion were observed on the tongue and in the nares of animals inoculated intradermolingually and also by the intravenous route. There was no clinical or serological reaction following contact or intranasal exposure. The excretion of virus and the development of neutralising antibody was investigated; more virus was detected in nasal than in oral swabs. The BA strain of Allerton virus was compared with two other African isolates by reciprocal neutralisation tests, using hyperimmune rabbit sera. No significant differences were demonstrable.